Natural gas is a naturally occurring gas mixture that is comprised of several different types of gas. Many natural gas fuel types are primarily mixtures of varying percent compositions that include gases such as: CH4 (methane), C3H8 (propane), C2H6 (ethane), C4H10 (butane), O2 (oxygen), N2 (nitrogen), H2S (hydrogen sulfide), and CO2 (carbon dioxide). There are a variety of professional suppliers of natural gas. In some instances natural gas supplied from these various suppliers may have a similar composition but will rarely be entirely the same. Accordingly, with different gas suppliers each supplying natural gas, the exact composition at any natural gas production site will vary among different regions.
Having information relating to the chemical composition of natural gas supplied by a particular gas source can be valuable for engine manufacturers and engine control system designers. For example, the fractions of species within certain natural gas supplies have large impacts on the knock, NOx, and lean burning limit capability of the engine. Hence, a need exists for an apparatus and method(s) for reliably predicting fuel type and composition of natural gas fuel provided by the various suppliers. Accordingly, the present disclosure provides an apparatus and method(s) for predicting fuel type and composition of natural gas based on sensitivities associated with measuring devices commonly used in vehicle engine applications.